Preventing the boys from panicking during their rescue is of the essence, New Zealand Diving's Neil Bennett told Al Jazeera.

"The training up to this point would be really focused on trying to keep them calm, explaining that they're going to be in poor visibility. Explaining that they have to keep the air supply in their mouth. It's really about dealing with the situation they're facing rather than trying to install perfect dive skills. That's never going to happen in this situation," he said.

"In a normal situation, you would have experienced professionals that might need rescue, not someone who's a complete novice who's never been in the water before, let alone who can't swim.

"So the real factor is trying to keep that panic element out of the way because that's where all the dangers come - as soon as someone panics then all sorts of problems come for the rescuers because a panicked diver can actually be a danger to the rescuer as much as themselves."

In a Facebook post, the Thai navy SEALs vow to bring the Wild Boars youth football team home.

"We, the Thai team and the international team will bring the Wild Boars home," the post reads.

On Saturday, the Thai navy SEALs posted notes from the football team on their Facebook page.

"I love you, Dad, Mum, and my sister. You don't need to be worried about me."

Thailand cave boys send handwritten letters to their families.

Anmar Mirza, a cave expert and US National Cave Rescue Commission coordinator, told Al Jazeera that the boys' weakness due to nine days of starvation makes the rescue operation risky.

"It takes a long time to recover and they have simply not had that time. I’m hoping that they have drilled well enough that there aren’t any problems but it’s still a huge risk," he said.

"The divers have built a level of trust with the boys and that's part of the psychology of getting them out. In most of the places, the diver can be right next to them. There are those few spots where they cannot be side by side, but again they can communicate with them by the fact that they're just right close there. So, with luck, that keeps them calm."

More than seven hours into the operation, the first boys make their way out of the cave.

Bangkok Post reported that a source told them the football team and their coach would be rescued in four batches: one of four and three of three people.

Rescue authorities said the coach will be the last to be brought out, Bangkok Post reported.

It is "unknown how long it will take before [rescuers] can bring out the first batch of boys," Chiang Rai Governor Narongsak Osottanakorn has said.

In a press release containing an update on the rescue mission, which has now been underway for more than eight hours, Osottanakorn said: "divers will work with medics in the cave to assess the boys' health before determining who will come out first".

"They cannot decide how many of them will be able to come out for the first operation. Based on the complexity and difficulty of the cave environment it is unknown how long it might take and how many children would exit the cave," the statement said.

The first two members of the football team have been recovered from the Tham Luang cave complex, a local official has told Reuters news agency.

"Two kids are out. They are currently at the field hospital near the cave," Tossathep Boonthong, chief of Chiang Rai's health department and part of the rescue team, said.

"We are giving them a physical examination. They have not been moved to Chiang Rai hospital yet."

Three boys have made their way out of the cave according to a military source, Al Jazeera's Scott Heidler has reported.

Thailand's interior minister is reportedly on the way to the field hospital, where the three boys are being assessed, Heidler said.

Two ambulances have been seen leaving Tham Luang and one helicopter has been heard taking off. Helicopters have been waiting to take the members of the football team to Chiang Rai's state capital where the boys and their coach will be treated in hospital.

In a Facebook post, the Thai Navy SEALs have said four members of the youth football team had exited the cave as of 19:47 local time (12:47 GMT)

Doctor Andrea Danese, a Psychiatry lecturer at King’s College in London, told Al Jazeera that he expects most of the children to present emotional symptoms.

"Several of them may be agitated, they may be irritable. They may be also acting out in terms of trying to deal with their emotions," he said.

According to Danese, 10-20 percent of the children may develop long-term mental health issues, such as "depression, anxiety, post-traumatic stress disorder … and in the older ones particularly perhaps substance abuse".

He also said that physical health issues may also occur due to malnutrition and high levels of stress.

I have been following this story and really thought I knew the whole story. You opened my eyes. I knew it was a miracle mission, but I had no idea it was this harrowing. Thank you for this compilation. God is with these kids and rescuers.

The most thorough explanatory article I have read to dat on this situation. Awesome job Lexy! Thank you for making it clear. The worthless MSM should take notes on the way you present information. God bless and KEEP WRITING!!